The identity of a baby's father can be discovered more quickly and cheaply since do-it-yourself DNA tests went on sale in high-street pharmacists in the US last month.
The $29.99 (£15) kits, with a further $119 (£60) for laboratory costs, sold so well in test marketing in the Pacific coast states that Sorenson Genomics of Salt Lake City, Utah, has rolled out its Identigene paternity kits across America. The kit consists of three cotton-bud swabs to take DNA samples from inside the cheek, one for baby, one for the putative father, and one for the mother, a consent form, three polythene pouches to keep the samples separate and an envelope addressed to the laboratory. Sorenson guarantees results by email within five business days.
Sorenson employs the same method forensic scientists use to determine DNA at crime scenes. The kits, which can establish paternity or prove genetic links between siblings with 99.9 per cent certainty, are being hailed as a breakthrough in resolving nagging family disputes. In the past, a DNA paternity test cost up to $2,000 and took up to six months.
There is no doubting the demand. The American Pregnancy Association reports that about 3 per cent of the 40,000 calls made to its hotline each year concern disputed paternity. According to Christine Rosen, a fellow at the Ethics and Public Policy Centre in Washington, DC, about one man in 25 in developed countries is unwittingly raising a child who is no blood relation. In Tennessee in 2006, about 2,000 of the 7,000 men named as fathers by women seeking child support turned out not to be the biological father.
Reasons for using the kits vary. The test altered the life of Wendy Lieb's 20-year-old son, who dropped out of university and found a job to support a woman who claimed he had made her pregnant at a party.
Lieb, of Lewis Center, Ohio, was concerned that the baby had no family resemblance. "He just didn't look like my son at all," she told a cable news channel. Within a week, an Identigene test proved the boy was not his.
Lieb was relieved it was so simple to establish the truth. "I thought it would have required thousands of dollars and a trip to the doctor," she said.
Sorenson stresses that the do-it-yourself tests are for "amusement only" and are not admissible in court, because the identity of those taking part cannot be verified. But the company will provide a legally sound test for about $350.
The test is not the answer to all identity disputes, however, warns R Alta Charo, a professor of law and bioethics at the University of Wisconsin at Madison. "We all need to take a step back and realise that this is different from many tests that you take. This is a life-changing moment," she says. Like with over-the-counter pregnancy and HIV/Aids tests, the result may cause the user to seek counselling.
Michael Watson, executive director of the American College of Medical Genetics, agrees that there may be unintended consequences. "It could break up families. Some will be broken because that was the goal. Others will be broken up and that wasn't the goal."
There can be other motives. Kristin Nelson, 27, of Nashville, said she would use a kit to silence her former boyfriend's parents, who doubt he is the father of her four-month-old son even though he accepts the boy as his own.
"I would do it to prove to his family, because some of them are going around telling people the baby is not his," she told the Tennessean. "I don't think they would treat me any better. I just want to prove them wrong."